Milking machine



Aug. 12, 1952 E. B. THOMPSON MILKING MACHINE 2 SHEETS-SHEET 1 Filed Feb. 25, 1949 'INVEN T02 Elmer fiwmpson 12, 1 E. B. THOMPSON 2,606,523

MILKING MACHINE Filed Feb. 25, 1949 2 SHEETS-SHEET 2 Fly. 4

Patented Aug. 12, 1952 MJLKING MACHINE Elmer B. Thompson, Des Moines, Iowa, assignor to Globe Hoist Company, Des Moines, Iowa, a

corporation of Iowa Application February 23, 1949, Serial No. 77,727

This invention relates machines and in particular to a portable milking machine of pulsator type having a power unit carried on a milk receptacle. I

In a milking machine of this type, and as shown in U. S. Patent 2,427,312, the power unit which is also located in the power unit housing.

The pump is air cooled and for this purpose the housing is formed with an air passage which extends about a portion of the pump. Air from the atmospheric chamber first enters the dis-, tributing means, for supply to the teat cup, is then returned to the air distributing means for admission to the pump inlet by way of the pump air cooling passage, andfrom the pump is discharged to the atmosphere.

Although this power unit inU. S. Patent2,42"1,-

312 is generallyv satisfactory in operation, the

generally to milking 3 Claims. (Cl. 119-144) flow of air through the teat cup and air distributing means, prior to its passage through the pump air cooling passage, has been found to be objectionable due to the fact that on any rupture of the teat cup inflation, milk is admitted-into the air cooling passage. By virtue of the length and construction of the air cooling passage any milk therein tends to remain rather than to'be moved therefrom by the pump. Further, since this passage becomes warm in the operation of the milking machina and can be thoroughly 1 cleaned only with some inconvenience and dimculty, the milk therein soonbecomes rancid and a self-contained. power unit in wmemneaaaz:

hausted from a teat cup is admitted directly to a pump inlet so that any milk entrained in the exhaust air is discharged from the power unit to the atmosphere.

Further objects, features and advantages of this invention will become apparent from the following description when taken in connection with the accompanying drawings, in which:

Fig. 1 is a side elevational view of a milking machine of pulsator type with a part of the power unit and a teat cup thereof broken away for the purpose of clarity;

Fig. 2 is an enlarged sectional view taken substantially on the line 2-2 in Fig. 1;

Fig. 3 is an enlarged sectional view as seen on the line 3-3 in Fig. 2;

Fig. 4 is an enlarged fragmentary exploded perspective view of the power unit with parts removed and other parts broken away to show the flow of air therethrough; and J 4 Fig. 5 is a sectional view taken along the line 5-5 in Fig. 4.

With reference to the drawings the power unit ID of this invention is illustrated in "Fig. l as including a motor II and an air distributing means 12 assembled within a main housing l4 having its bottom end closedfby a lower side wall or base [6. The base 16 is formed with a'center journal I! and a laterally extended annular flange l8. The under side of the flange i8 is formed with an annular recess .l9 tov receive a gasket 2 i, and the under side of the bottom wall it has an annular cut-away portion 22 to receive in a close fit the upper end of an annular casing or housing 23 for a pump of rotary eccentric type, generally indicated at 24.

The pump casing 23 is provided. with a cover 26 integrally formed with an annular lateral flange 21 venga-geable with the gasket 2| and terminating in an annular pocket 28 for receiving a gasket 29. The cover 26 and housing 23 are secured to the main housing M by screws 3|; It is thus seen that the motor H, air distributing means l2, and the pump 24 are fully enclosed by.

the housing I4 and casing 23 so that the power unit i0 is a package or self-contained unit. The gasket 29, when the power unit I0 is positioned over a milk receptacle 32, rests on the receptacle rim so that the power unit constitutes a cover for the receptacle. v

The motor ll (Fig. 1) has an upright shaft 33,

the upper end of which is suitably carried within the top end of the housing l4. Adjacent its lower end, the motor shaft 33 hasa worm section 34 positioned within a gear casing '36, that forms part of a body member 35 in the air distributing means l2, and a section 31 which is rotatably supported in a bearing 38 mounted in the base journal H. The lower end projects within the pump casing 23 and terminates in an eccentric 39 which is suitably connected with a pump rotor 30 to operate the same. A detailed description of the relative construction and assembly of the motor shaft II with the pump rotor 30 will be found in U. S. Patent 2,427,312.

The body member 35 of the air distributing means I2 is secured to the base [6 by screws 4| and extends laterally of the power unit I (Figs. 2 and 4), with an end section 42 thereof projected outwardly from the housing M at a po sition above the base l6. A rotary valve member 43 (Fig. 4) has a tubular stem 44 supported axially of the body member 35 and a head member 46 adapted to rotate in a seated engagement with a valve seat 41, which constitutes the bottom side of an annular cavity 48 formed in the outer or projected end 42 of the body member 35'. The inner or free end of the valve stem 44 projects through the gear casing 36' and within such casing carries a wormgear 49 which is in meshed engagement with the worm section 34 on the motor shaft. It-is seen, therefore, that the motorll, air distributing. means [2 and pump 24 are arranged in relative superposed positions within the power. unit Landwith the air distributing means and the pump being driven directly by the motor ll..

The cavity 48 (Fig. 4) is closed by a cover or cap i threaded about the projected end 42 of the body member 35 so as to be spaced from the valve head 46. An air chamber is thus formed by the cavity 48 and cap 46 which shall be referred to hereinafter as a subatmospheric air chamber, namely, a chamber having air therein at a subatmospheric pressure; An air passage 52 Within the tubular stem. 44 extendsradially and then axially through the valve head 46. so that the end 53 thereof is open to the valve seat 41. Thiaend 53 of the air passage 52 isof an.

arcuate. shape,. as best appears in Fig. 3,. and upon rotation of the valve member, passes in succession over a seriesjof spacedair openings.

54' formed in the valve seat 41. oppositely arranged from the arcuate passage end 53 and formed in the valve head member 46 is an arcuateslot 56, ofa longerlength th'an'the passage end" 53, which is .also arranged to passin. succession over the air openings 54.

The air openings 54 constitute one of the. ends of air passages 51*(Fig. 4), formed in thebody' powerunit: with teat cups 68. 'ojfj inflation type. For av more. detailed-description. of the valve.

head 46',,.-thej subatmospheric: chamber 48. and

air-passages, reference is made to U. S.-l atent'.

The endTl' ofithe-air, passage 52in thetubular' val'vestem. 44 constitutes an inlet for supplying.

air at an atmospheric pressure to the distributing means l-2, as will appear hereinafter. On rotation of the. valve member. 43-, therefore, air. at

anatmospheric orfhi-gh pressure is. suppliedto air. passages 5T f-rom theinlet 'H ,..a'nd air. at

gubatmospheric i pressure I is supplied". to the passages 51 from the subatmospheric chambers 48 through the arcuate slot 56. By virtue of the opposite arrangement of the passage end 53 and arcuate slot 56 in the head member 46, air is thus alternately supplied at high and low pressures to the air passages 51.

The pump casing 23 (Fig. 4) is of an annular shape and over that portion thereof, extended between the numerals A and A, is of a generally H-shape in transverse cross section, as best appears in Fig. 5. That part of the casing 23, which is of an H-shape, cooperates with the under side of the housing base I6 and the casing cover 26 to form upper and lower air passages within the casing 23 which are separated by a web 13. A baffle 14 extended across the upper passage divides this passage into an air passage 16 and an air chamber 11, while the lower passage 18 is continuous. The passages 16 and 18 constitute an air cooling passage for the pump 24, as will now be described.

One end 19 of the lower passage 18, which will be termed the inlet end of the air cooling passage, is open to the space 8! within the housing l4 (Fig. 4) by the provision of a hole 89 extended axially of the casing 23 adjacent to the end A of the H-shape casing portion and positioned for registry with an opening 82 formed in the housing base l6. At-the end A of the H-shape casing portionithe web member 13 is formed with an opening 84 to connect the upper air passage 16 with the lower air passage 18. That end 88 of the upper'air passage 16', adjacent to the baffle member 14 is arranged for registration with an opening 89 provided in the housing base l6, which opening 89 will here inafter be termed the outlet of the pump air cooling. passage. An elbow connection 9| (Figs. 2 and 4), secured to the top side of the housing base 16, connects the outlet 89 of the air cooling passage with the inlet H of the air distributing means I2.

Atmospheric" air is admittedto the housing.

space 81 throughopenings 92 formed in the an atmospheric'air chamber. Thus atmospheric air enters the inlet 19 of the pump air cooling passage through the registered openings and 82, as indicated by the--arrows94; flows through the lower air passage 18 and then upwardly therefrom through the opening 84 into the upper air passage 76, as shownby the arrows 96, and then outwardly and upwardly from the upperair passage 16 into the elbow 9-|, as illustratedby the arrows 91', to the inlet ll of the air distributingmeans l2.

From the air distributing means inlet H the atmospheric air flows through the valve stem passage 52=-to its end53 and into one'of thea-ir passages 5l as shown by the arrows 98 -The air inapassage 51 travels to a teat cup 68 throughthe conduit 63 to contract o'r d'epress the inflation 99 (shownin Fig. 1) in a-usual manner.

on registration of the slot" 56 in the head member 46, withan air passage-5'l, toconnect such passage with. the subatmospheric chamber-48 theair is' exhausted from. a teat" cup fiatoIprovide-fo'r areversed fiowof theair' in the passage 51,. as. indicated by .thearrow IO'I (Fig. 4)'-.It isapparent'thatwhen this reversed air flow takes place int the. inflation 99 is expandedi chamber 48" is maintained" at a subate mosphericg pressure by theprovision-of arrair passage I00, formed in the body member 35, and open to the chamber 48 so as to constitute an outlet at a subatmospheric pressure for the air distributing means I2. This outlet passage I is in registration with an opening I02 formed in the housing base I6 at a position opposite the pump inlet I03, which is at one end of an air chamber I04 formed in the pum casing 23 by the casing cover 26 and the housing base IS. The pump outlet I06 is at the opposite end of the air chamber I04, with the admission of air to and the discharge of air from the pump through a common cylinder opening I0'I being controlled by a rockable baffle member I08. Reference is made to U. S. Patent 2,427,312 for a more detailed description of the construction and operation of the bafiie member I08.

The pump outlet I06 is in registration with an opening I09 in the housing base I6, so as to connect this outlet with an exhaust air chamber III (Figs. 2 and 4) formed within the housing I4 and open to the atmosphere through exhaust openings H2 in the housing I4.

Thus as shown in Fig. 4, air from the subatmospheric chamber 48 is exhausted through the outlet passage I02 and into the pump inlet I03, as indicated by the arrows I13; from the pump inlet I03 into the cylinder opening I01 and through the pump 24, as shown by the arrows I I4; then outwardly through the opening I01 and into the pump outlet I04, as shown by the arrows H; and, finally, upwardly from the pump outlet I04'and through the opening I02 into the exhaust chamber III for discharge to the atmosphere through the exhaust openings II2, as indicated by the arrows II6.

Referring to Fig. 4, therefore, it is seen that air from the atmospheric chamber BI is initially directed to flow about the pump casing 23 through the air passages I8 and I6 prior to its admission into the air distributing means I2. After flowing through the air distributing means I2, the air is directed to the pump 24 for discharge to the atmosphere. By virtue of this travel of the air any milk that might become entrained in the air during its flow through a teat cup, as will occur in the event of any leakage through or rupture of the inflation 99, is positively withdrawn from the teat cup and air distributing means I2 by the suction action of the pump, and is then carried through the pump and positively discharged to the atmosphere by the pressure action of the pump. Any milk accumulations in the power unit I0, and the resultant objections to odors and cleaning, are thus entirely eliminated.

Further, it will be importantly noted that the serpentine cooling passage for the pump 24 carries only atmospheric air for admission to the air distributing means I2. This passageis thus entirely free of any milk that might be admitted into the air passages from a teat cup 66. Since only air alone is permitted to travel through the pump air cooling passage, no cleaning of this passage is required or is necessary.

The space within the milk receptacle 32 is maintained at a subatmospheric pressure by the provision of an opening I2I (Fig. 4) formed in the pump casing 23 for registration with the pump inlet I03. The pump cover 26 is provided with an opening (not shown) which is in alignment with the pump casing opening I2I. Air is thus exhausted directly from the milk receptacle into the pump inlet I03.

Although the invention has been described with respect to a preferred embodiment thereof it is to be understood that it is not to be so limited since changes and modifications can be made therein which are within the full intended scope of this invention, as defined by the appended claims.

I claim:

1. In a milking machine, an air distributing means for a teat cup, a rotary pump, having a casing, for evacuating air from said air distributing means, said air distributing means having an air intake portion and an air discharge portion, and said pump having an inlet and an outlet, with the casing for said pump being formed with a series of inter-connected air cooling passages having an inlet portion open to the atmosphere and an outlet portion, means fluid connecting said outlet portion with said air intake portion, and other means fluid connecting said air discharge portion with said pump inlet, with said pump outlet being open to the atmosphere.

2. In a milking machine, an air distributing means for a teat cup, a rotary pump for exhausting air from the air distributing means, said air distributing means having an air intake portion and an air discharge portion and said pump having an inlet and an outlet, 2. housing structure for said air distributing means and pump having an air inlet and an air outlet both of which are open to the atmosphere, with that portion of the housing structure enclosing said pump being formed with a series of interconnected cooling air passages having an inlet portion in fluid communication with the air inlet of said housing structure and an outlet portion, a fluid connection between the air intake portion for said air distributing means and said outlet portion, a second fluid connection between the discharge portion of said air distributing means and the inlet of said pump, and means fluid connecting the pump outlet with the air outlet for said housing structure.

3. In a milking machine, an air distributing unit for a teat cup and a rotary pump unit, having a casing, for exhausting air from said air distributing unit, said two units being arranged in a superposed relation, with said air distributing unit having an air intake portion and an air discharge portion and said pump having an inlet and an outlet, said casing being formed with a series of inter-connected air cooling passages havng an atmospheric inlet portion and an outlet portion terminating in the side of said casing adjacent to said air distributing unit, with the inlet and outlet for said pump unit being located in said adjacent side of the casing, and the air intake portion and air discharge portion for said air distributing unit being arranged in the side thereof adjacent to said casing, said two units being relatively arranged so that said passage outlet portion and said discharge portion are in registration, respectively, with said air intake portion and said pump unit inlet, with said outlet of the pump unit being open to the atmosphere.

ELMER B. THOMPSON.

' file of this patent:

UNITED STATES PATENTS Name Date Thompson et a1. Sept. 9, 1947 Number 

